As part of a long-term research effort investigating the impact of laws and public policies on health care for the elderly, this project will estimate the effects of laws governing living wills on medical treatment decisions, health care costs, and health care outcomes in the elderly. The project has four main objectives. The first is to compile and integrate comprehensive national data on changes to living will and other laws from 1984-1995 with longitudinal hospital-level data and longitudinal individual-level data on medical treatment decisions, health care costs, and health care outcomes in the elderly for a range of medical conditions. The second goal is to identify subpopulations of elderly patients for whom living wills have the greatest impact, including those with major illness and those near the end-of-life. The third goal is to identify the determinants of living will law changes and other state legal reforms. The fourth goal is to assess the effect of different dimensions of living will laws and changes in these laws on medical treatment patterns, health care costs, and health outcomes, focusing on subpopulations of elderly individuals most affected by public policy toward living wills. Since living will laws frequently contain multiple provisions with potentially opposing impacts, the project will identify separately the influence of different dimensions of law changes on patient and physician decision-making and health outcomes. In addition, the project will investigate whether living will laws interact with hospital characteristics, area characteristics, and other laws influencing medical treatment patterns. Our methods identify the effect of public policies toward living wills by comparing trends over time in intensity and outcomes for patients from states that changed their laws to patients from states that did not. Because the role of a living will is completely specified by state law, these methods will directly address the crucial public question of interest: how do different types of living will laws, that grant patients different rights, affect treatment decisions, health care costs, and health outcomes?